diff --git a/.ruby-version b/.ruby-version
index c063f5a..bed811b 100644
--- a/.ruby-version
+++ b/.ruby-version
@@ -1 +1 @@
-ruby-2.2.4
+ruby-2.3.3
diff --git a/.travis.yml b/.travis.yml
index 63dfce3..d0db021 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,8 +1,8 @@
 language: ruby
 rvm:
-- 2.1.4
-- 2.0.0
-before_install: 
+- 2.1.5
+- 2.3.3
+before_install:
   - gem install bundler
 deploy:
   provider: rubygems
diff --git a/jenkins_pipeline_builder.gemspec b/jenkins_pipeline_builder.gemspec
index f57123c..6d2a3b6 100644
--- a/jenkins_pipeline_builder.gemspec
+++ b/jenkins_pipeline_builder.gemspec
@@ -23,11 +23,11 @@ automating Job & Pipeline creation from the YAML files checked-in with your appl
 
   spec.add_dependency 'nokogiri', '~> 1.6.0'
   spec.add_dependency 'jenkins_api_client', '~> 1.0.0'
+  spec.add_dependency 'mixlib_shellout', '= 2.2.6' # maintaining backwards compatibility with ruby 2.1.5
   spec.add_dependency 'thor', '>= 0.18.0'
   spec.add_dependency 'activesupport', '~> 4.2.6'
   spec.add_dependency 'minitar'
 
-  spec.add_development_dependency 'bundler', '~> 1.14.6'
   spec.add_development_dependency 'rake'
   spec.add_development_dependency 'rspec', '~> 3.0'
   spec.add_development_dependency 'bump'